Digital display device for surface-roughness measuring instruments



FIG. 1 is a front perspective view of a digital display device for surface-roughness measuring instruments showing our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a right-side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines depict environmental subject matter only and form no part of the claimed design. 

CLAIM We claim the ornamental design for a digital display device for surface-roughness measuring instruments, as shown and described. 